Jack assemblage



March 23,1943. v s, MANDL 2,314,589

JACK ASSEMBLAGE Filed June 14, 1941 I 1 rlllulllllluml '4 'ATTORNEY.

Patented Mar. 23, 1943 JACK sssamnmca SiegmundfMandl, Milwaukee, Wla, assignor to Blackhawk Mfg. 00., Milwaukee, Wis., a 0011109 ration of Wisconsin Application June 14, 1941, Serial No. 398,058

Claims.

The present invention relates to improvements in the art of elevating or lifting diverse objects, and relates more particularly to improvements in the construction and operation of Jackassemblages for raising vehicles such as airplanes or the like.

An object of the inventionis to provide a new and useful Jack'assemblage especially adapted to effect convenientvand safe lifting and lowering of relatively frail and bulky bodies such as airplanes or the like, while grounded.

It is frequently desirable in connection with aviation, to provide means for raising and lowering various portions of an airplane structure while grounded, and any lifting devices adapted for thisclass of service must be quickly and safely operable and should have a relativelylong range of movement. Since considerable power is required to raise large planes, it is desirable to utilize hydraulic elevating means; and because of the fact that several lifting units must often be utilized to elevate a single ship and to hold the same in elevated condition, it is also desirable to be able to remove the hydraulic hoisting mechanism from the prop portions of the lifting assemblages, and to interchangeably apply the same hydraulic mechanism to numerous other prop assemblages of similar type, while the previously elevated prop structures remain in use.

The use of hydraulic power means also makes it possible to employ a single pressure source to actuate a plurality of lifting jacks and props from a centralstation, and to thereby accurately and safely control the raising and lowering.

It is therefore a more specific object of my present invention to provide an improved airplane jack assemblage which meets all of the above mentioned special. requirements, and wherein the power system may be readily re-, moved from one prop aessembly and interchangeably applied to another.

Another specific object of this invention is to provide an improved tripod prop assembly which can be quicklyand conveniently extended to great length, and locked in extended condition- A further specific object of the invention is to provide an improved hydraulically actuated airplane jack mechanism, which is durable in construction and compact in form.

Still another specific object of my invention is to provide an improved lifting and propping unit, provided with compact and powerful means for safely raisins and lowering diverse bodies, and which is especially adapted for cooperation with v relatively frail parts such as the wings and landing gear of airplanes.

'An additional specific object of the present,

which may be readily assembled i'for'normal use.

A further specific object of this invention is to provide an improved hoisting assemblage operable by a hydraulic ram, and wherein a relatively standard short stroke ram may be effectively utilized to produce long range lifting.

Another, specific object of my invention is to provide a combined prop and jack assembly, in which the jack unit may be readily attached to the prop: or removed therefrom for use with other similar props, whilejthe initially elongated prop is retained in extended condition and in active service.

Still another specific object of the invention is to provide a simplified airplane jack assemblage which can be manufactured and sold at moderate cost, and which is highly efiicient in use and flexible in its adaptations.

These and other specific objects and advantages of the present invention will be apparent from the following detailed description.

A clear conception of the several features which constitute the present improvement, and of the mode of constructing and of utilizing the improved jack assemblages, may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views.

Fig. 1 is a central vertical section through one of the improved tripod props showing a hydraulic sump and jack system applied thereto in eleva- Fig. 2 is a fragment of the jack and prop assemblage, but showing a modified type of extension, member for the prop, and also showing a modified fitting applied to the Jack;

Fig. 3 is a transverse section through the asseniiblage of Fig. 2, taken along the line 3-4; an

Fig. 4 is another fragment of the jack and prop assemblage, showing a further modified type of extension member for the prop.

While the features of the present invention have been shown and described herein, as being specifically embodied in a tripod prop equipped with a detachable hydraulic pump and ram, and adapted to'be operated in upright position, it is not intended to thereby unnecessarily limit the invention or the utility of the several features constituting the improvement.

Referring to the drawing, the improved prop and jack assemblage comprises in general a tripod structure having three or more tubular legs 8 detachably secured at their upper ends to an upper bracket or central hub and being provided at their lower ends with pads or feet 8; an elongated extension or tubular member 9 slidably confined within a central bore ID in the upper hub 1, and in a medial guide bearing carried by the legs 6, and having two series of transverse apertures or holes l2, I3 therein adapted for the reception of removable lower and upper pins l4, IS; a hydraulic ram or Jack having. a cylinder l6 adapted to rest upon a central base pad secured to the tripod feet 8, in axial alinement with the member 9 and bore Hi, and also having a piston or plunger movable in the ,The tripod of the prop should be of rigid construction when assembled, but should also be collapsible so that it can be confined in compact condition'and in small space, when notinuse. The supporting legs 6 may therefore beformed of stiff tubing. and the upper ends thereof may either be detachably secured to the bored central hub I in any suitable manner as by screw threads 23, or they may be pivotally attached to the hub structure The supporting feet 8 may be'likewise detachably secured to the lower ends of the tubular legs 8, and the central base pad should be flrmly secured to these feet I or to the legs 8 as by means of detachable links 24 radiating from the central axis of the tripod. The elongated tubular extension member 9 which is snugly but slidably confined within the hub bore l and guide bearing I I, may be formed of a piece of strong pipe; and the transverse apertures or through holes l2, I: are preferably arranged in two sets located in planes perpendicular to each other, in order to avoid undesirable weakening of the prop member 9. The holes l2; l9 are spaced equi-distant apart and may all be of the same size; and the two pins l4, l are likewise of the same size, and are adapted to be interchangeably inserted in any alined pair of holes |2, |3 so that the lower pin l4 will provide an internal abutment spanning the interior of the member 9, while the upp r pin l5 which is longer than the lower pin M will project outwardly beyond the opposite sides of the member 9 considerable distances and may be caused to en age the top of the hub 1. These pins l4, I! may be secured to adjacent structure by means of chains or flexible connectors 25, and while the upper end of the tubular member 9 may be closed by awork engaging fitting 26 of suitable formation, the lower end is open for the reception of the lifting Jack. a

The ram or jack is of relatively standard construction, and the ram cylinder It may be rigidly removably connected to the base plate or pad I! in any suitable manner as by'screw threads,

so that the axis of the cylinder l8 will 'be con-' centric with the axis of the hollow member 9.

The ram plunger l1 may have a relatively short stroke somewhat greater than the distance between successive holes l2, l3, and preferably also reater than twice the distance between the successive equally spaced holes; and the upper end of the plunger may be screw threaded or otherwise formed for detachable reception of a short adapter 21 such as shown in Fig. 1, or a longer adapter 28 as shown in Fig. 2. The plunger l1 and the adapters 21, 28 are freely vertically movable within the tubular member 9, and the adapters are capable of engaging the lower abutment pin It as in Figs. 1 and 2 in order to impart elevatingmotion to the member when liquid under pressure is admitted to the ram displacement chamber.

In order to permit convenient application of the ram unit to the base plate II, or removal thereof, without necessitating excessive lifting and lowering of the central member 9, the lower end of this tubular member may be formed either as shown in Figs. 2 and'3, or as disclosed in Fig. 4. In Figs. 2 and 3, the lower end of the member 9' has been provided with aside'opening or slot 29 through which the ram unitmay be inserted laterally, and the lower holes l3 have been disposed in the same plane with the holes l2. In Fig. 4, the lower end of the tubular member 9" has been provided with a removable extension 29' attached to the lower extremity of the member 9 by a detachable coupling sleeve 30; and when this sleeve 30 is released from either of the adjacent tubular sections, the extension 29' may be shifted laterally with the ram assembly and relative to the-tubular member 9".

The manually operable pump unit which -communicates with the ram cylinder 16 through the flexible tubular connection 22, is provided-with feet 3| on the casing l8 which are interlockablewith a lower bracket 32 secured to one of the tripod legs 6, and the upper end of'the pump supply reservoir 2| is provided with a closure cap 33 havinga projection 34, with which a pivoted locking latch 35 carried by an upper bracket 36,- is cooperable. The arrangement is such that when the latch 35 is in midposition, the pump is firmly attached to-the tripod leg 8 and the handle 20 may be oscillated to reciprocate the piston l9, thereby forcing liquid from the reservoir 2| into the ram cylinder l6; and the pump is also provided with a by-pass or return valve 31' for permitting free return of liquid from the ram displacement chamber to the reservoir 2| through the connection 22 and casing l8 when-the ram plunger I1 is' being lowered; The upper bracket may cooperate with similar brackets onthe other tripod legs 6, to rigidly but detachably support the central guide bearing II in perfect alinement with the bore ID of the upper hub 1. The hose connection 22 is preferably provided with a quick detachable coupling 39 for permitting removal of the pump without removing the ram, and the cylinder l6 of the ram may be provided with a valve 38 for preventing escape of liquid from the ram displacement chamber when the hose 22 is disconnected. 1

During normal use of the improved prop and jack assembly, several of the'props may be provided for interchangeable cooperation with a single hydraulic jack and pump unit. After the pump and Jack have been properly attached to the tripod leg 6 and pad respectively, as illustrated in Fig. 1, the lower abutment pin l4 may be inserted within the set of holes l2, 13 directly' above the upper end of the ram plunger l1 while this plunger is in lowermost position. The pump handle 20 may then be oscillated to force liquid under pressure from the reservoir the upper limit of its stroke, the upper pin I! may be inserted in the set of holes I2, I3 di-' rectly above the top of the hub I, whereupon the ram plunger l 1' maybe lowered and the upper pin IE will become effective to retain the member 9 in elevated position. If additional lifting is thereafter required, the lower pin l4 may be withdrawn and inserted in a new set of holes l2, l3 located directly above the lowered plunger l1, and after the desired additional elevation has been effected by subsequent raising of the ram plunger 11, the upper pin 45 may be readjusted to a new set of holes I2, l3 directly above thehllb I toagain hold the member 9 in its newly elevated position. Additional lifting of thetubular member 9 beyond the extreme range of the ram alone, can also be effected by utilizing adapters 21, 28 of different lengths, but the strut member 9 should not be elevated above the guide bearing I l. The ram and pump units may obviously be removed from the prop assembly at any time after the upper pin l has been inserted and become effective, and the hydraulic units may then beapplied to other similar prop assemblages without disturbing the initial or original prop. The pump alone may be removed from the assemblage, by utilizing the shut-off valve 38 to prevent escape of liquid from the cylinder is, and by thereafter disconnecting the coupling 39 which may be provided with a check valve for preventing subsequent escape of liquid from the hose connection 22.

Either of the modifications shown in Figs. 2 and 3, or in Fig. 4, may be utilized to facilitate application and removal of the ram with respect to the pad l1; and any desired, number of adapters 21, 28 of different lengths may be utilized. While these adapters are preferably associated with the ram plunger l1, they may also be inserted between the ram cylinder l3 and the supporting pad IT. The pump unit may be quickly and readily removed from the brackets 32, 36 by merely releasing the latch 35 and by subsequently raising the entire unit to free the feet 3| from the bracket 32. The pump and the connection 22 may also be released from the ram unit with little effort and without permitting undesirable escape of liquid, and the prop assemblage may be readily dismantled.

From the foregoing detailed description it will be apparent that the present invention provides an improved prop and jack assemblage which besides being simple, compact and durable in construction, is also highly eflicient in operation and can be safely manipulated to meet diverse conditions of use. By utilizing a hydraulic ram and pump, great power can be applied with a hydraulic unit of light weight and small size, and by making the hydraulic units detachably cooperable with a plurality of similar prop assemblages, the total cost is reduced to a minimum, and the props may be left in elevated active condition after the pump and ram have been removed. The pump may also be removed from the prop assembly, and a single pump or elevated.

other pressure source located at a common station may thereafter be utilized to actuate a plurality of rams each associated with an independent prop. This feature is of considerable importance in the aviation industry, and besides facilitating application of power to several pro s, the hydraulic system eliminates undesirable reaction forces due to power application and possible resultant displacement of the Jack from the load. The holding pins I4, l-5 may be of like construction, and the pin l5 which retains the member 9 in elevated position greatly adds to the safety of the equipment by preventing accidental lowering of the tubular member in case of leakage of liquid from the hydraulic system or for any otherreason, and the improved prop assembly is especially adapted for airplane service, because of the long active range of travel or adjustment available for the work engaging member 9. The improved combination of elements can be produced from relatively standard parts and equipment, and can therefore be manufactured and sold at moderate cost.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of use, herein shown and described, because various modificationswithin the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. In combination, a tripod having a vertical central bore, a tubular extension member slidable in said bore and having a series of transverse through holes, a jack having a plunger disposable within said member and cooperable with a pin piercing selected sets of alined holes of said series to raise said member, and another pin cooperable with said tripod and with other of said holes to retain said member in various positions of vertical adjustment.

2. In combination, a tripod having an upper hub and a lower base plate and legs interconnecting said hub and plate, said hub having a guide surface in axial alinement with said plate, a tubular member slidably cooperable with said lower apertures of said series, one of said ele ments being cooperable with'iasai'd plunger to cause the same to elevate said member and another of said elements being cooperable with said hub to retain said member in elevated position.

3. In combination, a tripod having an upper hub and a lower base plate and legs interconnecting said hub and plate, said hub having a guide surface in axial alinement with said plate, a tubular member slidably cooperable with said surface and having a series of transverse apertures therein, a jack having a cylinder detachably cooperable with said base plate and a plunger movable within said tubular member liquid supply pump detachably associated with one of said legs and being connected to said Jack, and a pair of pins cooperable with upper and lower aperturesof said series, one of said pins being cooperable with said plunger to cause the latter to lift said member and the other pin being cooperable with said hub toretain said member 4. In combination, a tripod having an upright bore, atubular member slidably cooperabiewith pins cooperable with said apertures to provide a lower lifting abutment and to hold said mem.

ber in elevated position, and a hydraulic jack having a movable plunger cooperable with said lower lifting abutment within said tubular member to elevate the latter.

5. In combination, a tripod having an upright bore, a tubular member slidable in said bore and having two series of through holes disposed in different planes, an upper pin cooperable with the holes of either of said series and with said tripod to retain said member in elevated position, a lower pin cooperable with the holes of either of said series to provide ,anabutment within said member, and a hydraulic jack having a plunger cooperable with said abutment within said tubular member to elevate said member.

6. In combination, a tripod having a bore, a tubular member slidable in said bore and having a series of holes therein, a pin cooperable with said holes and with said tripod to retain said member in various positions of adjustment, an-

other pin cooperable with said holes to provide an abutment disposed various distances from an end of said member, a jack having a plunger movable within said tubular member, and adapters of different lengths interposable between said plunger and said abutment pin.

7. In combination, a tripod having a bore at one end and a fixed bearing plate spaced from but located in alinement with said bore, a tubular member slidable in said bore toward and away from said plate, a jack mounted upon said plate and being disposable within and cooperable with said member to slide the latter within said bore, and means for facilitating application and removal of said jack to and from said plate when said member is in extreme position nearest said jack 8. In combination, a prop having a tripod and a work supporting member adjustable relative to said tripod, a. hydraulic ram attachable to said tripod and being cooperable with said member to adjust the same relative to the tripod, a liquid pump for actuating said ram and formed for attachment to said tripod, and means for effecting removal of said ram and pump as a unit and for effecting detachable attachment thereof to other similar tripods,

9. In combination, a prop having a tripod and a work supporting member adjustable-relative to said'tripod, a hydraulic ram attachable to said tripod and being cooperable with said member to adjust the same relative to the tripod, a liquid pump for actuating said ram and formed for attachment to said tripod, means for effecting removal of said ram and pump as a unit and for eflecting detachable attachment thereof to other similar tripods, and means for retaining said member in various positions of adjustment when i said ram has been removed.

10. In combination, a prop having a tripod and a work support adjustable relative to the tripod, a hydraulic ram associable with said tripod for cooperation with said support to adjust the latter relative to said tripod, a liquid pressure producing 

